Simultaneous real-time echocardiographic imaging of myocardial perfusion and regional function using color-encoded, contrast-enhanced power modulation

Abstract

We hypothesized that color-encoded, contrast-enhanced, power modulation imaging could allow simultaneous quantification of myocardial perfusion and regional left ventricular function. We studied 12 anesthetized, closed-chest pigs at baseline, during acute ischemia, and during reperfusion, and 8 patients after acute myocardial infarction. Color kinesis was used to color encode endocardial motion during real-time contrast perfusion imaging with high-energy ultrasound pulses. Wall motion was assessed by calculating regional fractional area changes. Translation-free perfusion analysis was performed in automatically identified myocardial regions of interest. Steady-state intensity and postimpulse rate of contrast replenishment were calculated. In all animals, ischemia caused reversible changes in the images and the perfusion- and function-calculated indices. A significant decrease in pixel intensity (14%) and contrast replenishment rate (66%) in left anterior descending coronary artery segments, in agreement with fluorescent microspheres measurements, coincided with a decrease in fractional area change (34%). For patients, respective perfusion and function indices were 61%, 51%, and 58% lower in segments where perfusion defects, regional wall-motion abnormalities, or both were noted in gray scale images. Color-encoded, contrast-enhanced power modulation allows simultaneous real-time imaging and quantitative analysis of myocardial perfusion and regional left ventricular function.